The present disclosure relates to a field bus network adapter and a field bus network subscriber each provided with a plurality of field bus connections.
The present disclosure lies in the field of field bus networks. Field bus networks are used as industrial networks in order to connect individual components of industrial machines to one another and to an associated control unit which controls the sequences in the machine. Known field buses are, for example, Sercos, Profinet, etc. Typical industrial machines are printing machines, packaging machines, industrial robots, conveyor belts etc.
Systems with real-time capability are being increasingly used in the field of field buses. “Real-time capability” is understood as meaning that the movements of the connected units, for example printing units, robot arms, conveying mechanisms etc., can take place in a defined temporal relationship with respect to one another. This is vital for the operation of particular industrial machines, such as printing machines or robots, in order to ensure, for example, collisions between robot arms or between robot arms and the material, to ensure register accuracy of printing operations etc.
Even though field buses are therefore occasionally set up on known network topologies, for example Ethernet in the case of Sercos III, solutions which are known from conventional network technology (for example in TCP/IP) cannot be readily applied to field buses. Ethernet-based field buses with real-time capability are cited, for example, in the IEC 61784-2 standard.
The systems cabled using field buses are subject to certain demands imposed on operational readiness and response in the event of a fault. For reasons of operational reliability and redundancy, certain field buses use a logical ring structure (one supply line and one return line) or a double-ring structure (two supply lines and two return lines). The supply line and the return line are physically usually accommodated in one cable, which is why the logical double-ring structure is implemented in the form of a physical single-ring structure and the logical ring structure is implemented in the form of a physical line structure. However, a physical star topology is not possible, which makes the cabling relatively complicated overall, in particular if a new network subscriber is intended to be added to an existing field bus network.
In summary, it is relatively complicated to insert new network subscribers into existing networks since a plurality of cables are always required in order to obtain the physical line or ring topology (at least one there and one back). This is undesirable in practice.
Therefore, the object of the disclosure is to specify a possibility which can be used to reduce the cabling complexity in field bus networks with a line or ring topology without making changes to the transmission technology on which the bus is based, with the result that the disclosure can also be implemented, in particular, in existing field bus networks. In particular, the intention is to make it possible to insert a new subscriber into an existing field bus network via a single cable.